package chapter04.demo1;
import java.sql.*;
import java.util.Scanner;

public class demo1 {
    public static void main(String[] args) throws SQLException{
        //修改用户名和密码
        /**
         * 1.注册驱动
         * 2.获取连接
         * 3.创建表结构对象
         * 4.执行SQL语句
         * 5.操作结果
         * 6.关闭连接
         */
        Statement stmt = null;
        ResultSet rs = null;
        Connection conn = null;
        try {
            //1.注册数据库的驱动
            Class.forName("com.mysql.cj.jdbc.Driver");
            //2.通过DriveManger获取数据库连接
            String url =
                    "jdbc:mysql://localhost:3306/jdbc?serverTimezone=GMT%2B8&useSSL=false";
            String username="root";//数据库名称
            String password="123456";
            conn=DriverManager.getConnection(url,username,password);
            /**
             * 静态sql语句用 Statement
             * 动态sql语句用 PreparedStatement
             */
            Scanner sc=new Scanner(System.in);
            System.out.println("请输入你的旧账号名");
            String n1=sc.next();
            System.out.println("请输入你的旧密码");
            String p1=sc.next();
            System.out.println("请输入你的新账号名");
            String n2=sc.next();
            System.out.println("请输入你的新密码");
            String p2=sc.next();
            String updateSQL="update users set name=? , password=? where name=? and password=?";
            PreparedStatement ps=conn.prepareStatement(updateSQL);
            ps.setString(1,n2);
            ps.setString(2,p2);
            ps.setString(3,n1);
            ps.setString(4,p1);
            int res=  ps.executeUpdate();
            System.out.println(res);
            if (res>0){
                System.out.println("账号密码更新成功");
            }else {
                System.out.println("账号密码更新失败");
            }
        }catch(ClassNotFoundException e ){
            e.printStackTrace();
        }finally{
            //6.回收数据库资源
            if (rs != null);{
                try{
                    rs.close();
                }catch(SQLException e){
                    e.printStackTrace();
                }
                rs=null;
            }
            if (stmt!=null){
                try{
                    stmt.close();
                }catch (SQLException e){
                    e.printStackTrace();
                }
                stmt = null;
            }
            if (conn != null){
                try{
                    conn.close();
                }catch (SQLException e){
                    e.printStackTrace();
                }
                conn = null;
            }
        }
    }
}
